Roof racks for vehicles have enjoyed continued popularity for many decades. Roof racks are well suited for the transport of bulky objects, in particular when the use of a trailer is not required or not desired. This is due, for example, to the lower purchase costs of a roof rack (relative to trailers), the reduced space requirement and reduced operating restrictions (no strict mandatory speed limit or the like). An example of the use of roof racks which is seen very frequently is for the transport of skis or other winter sports equipment.
In order to keep the air resistance of the vehicle as low as possible, in particular also for reasons of the energy efficiency thereof, roof racks are generally designed to be able to be assembled/dismantled in a reversible manner, since during most of the time when the vehicle is used they are not required and thus weight and air resistance may be reduced. In order to be able to assemble roof racks, a suitable assembly structure has to be accordingly provided on the roof of a vehicle. In this case, a structure is to be provided, said structure being able to receive sufficiently large loads, being relatively advantageous in terms of production and assembly, being suitable for the assembly of the largest possible number of roof racks (if possible substantially irrespective of the manufacturer) and, in particular in “normal operation” without a roof rack, having an air resistance which is as low as possible. In particular, in order to ensure the ability to assemble the largest possible number of different types of roof racks, the fastening rails for roof racks which are known per se and have been used and proved effective over many years are still the preferred technical means for the assembly of roof racks.
However, there is still the need for improvement with regard to the fastening of the fastening rail to the vehicle itself (more specifically: in the region of the vehicle roof). Here attempts are still being made to fulfil a range of partially conflicting interests in a manner which is as advantageous as possible, such as for example load-bearing capacity values which are as high as possible, capacity for easy assembly, replaceability of the fastening rail in the case of damage, cost-effective production, etc. Since in this respect there was always the need for optimization, over the years a plurality of proposed solutions have been made.
For example, in U.S. Pat. No. 5,782,392 it is proposed to provide a vehicle roof with longitudinal grooves which extend in the direction of the vehicle longitudinal axis. A corresponding protruding bulged region of a roof rack fastening device may be inserted by its cross section into the longitudinal grooves, resulting in a substantially flush surface of the vehicle roof. The bulged region is screwed onto the roof structure by means of fastening screws. A rail body which has a cross section extends from the fastening bulge so that a roof rack may be fastened thereto by fastening clips. Although the fastening rails described therein have advantageous air resistance properties and an advantageous appearance, the fastening of the fastening rail to the vehicle roof is relatively complex. A further drawback is that the vehicle roof is relatively complex to design, due to the required groove, in order to be suitable for the system proposed therein.
A further proposal has been made by FR 3017087 B 1. In this case a fastening rail extending in the vehicle longitudinal axis is also fastened by a plurality of fastening screws to a vehicle roof. In this case, the assembly of the fastening rail is also relatively complex.
A further proposal is disclosed in FR 2993219 A1 in which it is also proposed to fasten a fastening rail for roof racks extending in the longitudinal direction of the motor vehicle roof by means of a plurality of fastening screws to the vehicle roof. In this case the assembly is also relatively complex.
Whilst the known fastening rails and/or the assembly thereof on a vehicle roof generally fulfill the assigned functions to a sufficient extent, there is still further room for improvement.